bad USB dongle causes shutdown?

[Jakey The Avatar]

This evening I sat down to relax, intent on watching a bit of Monty Python's Flying Circus, when suddenly my HTPC decided it was time to power off.

At first I thought perhaps Vista had downloaded something which required it to restart, and the unit simply failed to restart. Not a problem I'll just get up and turn it back on again...

I'm sure many of you can imagine the sinking feeling that spread throughout my stomach when I pressed the power button and nothing happened.

Ok, let's reset the bios and see what happens. Hmm, no change.

Next I thought, perhaps it is the power supply. The PSU came with the case and I generally hold such PSU's in low regard. So I whipped out my trusty paper clip, short the green to a black, and low and behold we have power.

At this point I really began to panic, as I now begin to think it is the motherboard. But wait, there are other things to check.
Ok. Let us remove some peripherals and see what happens.... Wait, even better, let's remove them one at a time and check after each...
Mouse out. No change.
Keyboard out. No change.
Remote receiver out. No change.
USB Wireless (via dongle) out. We have power!
Hmmm. That was unexpected.

Ok, let's plug everything else back in...
Ok still good.
Let's plug in the USB wireless (via dongle).
Oh, there it goes. It's shutdown again.

Ok. Well, that's a bummer. I don't have another USB wireless. I wonder if the dongle could be the problem?
So, I remove the dongle and plug USB wireless directly into the computer and... everything is fine.
Again, not what I expected.

So, now that the computer is working fine again (for now at least), we come to the questions:
Is the dongle really the most likely culprit in this case?
or
Is this more likely a precursor to some form of horrible system failure?


also
Lemon curry?

[Darkstar]

could be the dongles driver, did you try it on another usb port? i have had systems shut down when plugging in a front usb (Antec) but that was due to the action of plugging in the usb causing a short.

[Sporg]

I'd say it's a short in the dongle. If I read your post correctly it shuts down as soon as you plug it (dongle) in. Did you try the dongle (I love typing that word) in another USB port?

Oh, and good logical troubleshooting to find the culprit!

[Jakey The Avatar]

Indeed, I forgot to mention it in the original post, but I did try the dongle (yes that is a fun word) in different USB ports. Specifically I tried both sets on the motherboard panel (on the back) and both sets on the front of the case. The result was consistent throughout, immediate loss of power.

The only thing I did not try was to plug in the dongle without the USB wireless connected to it. Perhaps I'll try that when I get home from work later.

Cheers!

[Darkstar]

You reinstall the driver for it?